The present invention relates to a device for diverting an imbricated flow of printed products that is transported on a roller table having a plurality of rollers arranged one behind the other.
Roller tables of this kind are used for transporting imbricated flows of printed products especially in printing plants. The term imbricated flow of printed products is used to describe a number of flat and relatively flexible printed articles, such as newspapers, leaflets or magazines, which are arranged one behind the other and partially overlap each other. Roller tables have been employed heretofore for transporting imbricated flows of printed products transversely to the lengthwise direction of the rollers. In many cases, however, a need exists to divert an imbricated flow or to vary the direction of an imbricated flow depending on the requirements of the particular case.
The use of special roller tables also permits imbricated flows of printed products to be transported along curved paths. Such special roller tables comprise for this purpose conically shaped rollers arranged one behind the other along a curved path. The path of each roller table is, however, firmly defined by the particular arrangement of the rollers.
In the case of another known device, the imbricated flow of printed products is transported on broad belts that revolve between two diverting rollers. The belts can be mounted on the diverting rollers in different positions so that the direction of the imbricated flow can be varied by changing the position of the belts on the diverting rollers. However, operation necessarily has to be interrupted in this case for any change in direction.
In addition, there have been known roller tables for transportation of stiffer objects, such as cardboard boxes, where baffle plates are arranged above the rollers that divert the objects on the roller table in lateral direction. Such plates are, however, not suited for changing the direction of imbricated flows of printed products because due to their small thickness and their flexibility these tend to duck under the baffle plates and to get jammed in the gap between the rollers and the baffle plates.
It is the object of the invention to provide a device for diverting an imbricated flow of printed products on a roller table, which allows even relatively flexible imbricated flows of printed products to be diverted on a roller table of that kind. The diverting direction should be freely selectable within predetermined limits.
This object is achieved by a device comprising an elongated adjustment member whose position can be varied within a sliding plane extending in parallel to a transportation plane defined by the rollers. The device further comprises a plurality of guide elements for guiding the flow, the guide elements extending into clearances formed between every two rollers and being received on the adjustment member for rotation relative to the adjustment member in a direction perpendicular to the sliding plane and for sliding movement in lengthwise direction of the adjustment member.
By having the guide elements extending into the clearance between every two rollers, one efficiently prevents the rollers and the guide elements from forming between them a gap of a kind in which the imbricated flow may get jammed. This tendency of the imbricated flow, namely to get jammed when moving in oblique direction relative to the transport direction defined by the rotation of the rollers, is due to the small thickness and the comparatively high degree of flexibility of the printed products.
Due to the fact that the guide elements are mounted on the adjustment member for rotation in a direction perpendicular to the sliding plane and for displacement in the lengthwise direction of the adjustment member, the diverting sense can be varied as desired, at least within defined limits, which means that a choice is provided not only between left or right, but also with respect to the diverting angle. During variation of the direction of the adjustment member, the guide elements only move in the lengthwise direction of the rollers so that the clearances between the rollers remain filled by the guide elements.
According to a preferred embodiment of the invention, each of the guide elements is provided on its bottom, facing the rollers, with two oppositely arranged partially cylindrical recesses having a contour that substantially corresponds to an outer surface of the rollers. This results in a minimal gap remaining between the rollers and the guide elements, which is necessary to allow rotation of the rollers under the guide elements. It is, thus, practically excluded that an imbricated flow of printed products guided on the device may get jammed between the guide elements and the rollers or between different rollers.
According to another advantageous embodiment of the invention, the adjustment member comprises two parallel, mutually spaced bars that define a gap. Each of the guide elements comprises a journal projecting from its upper surface opposite the rollers and engaging into the gap. This embodiment permits, in a constructionally very simple way, rotation of the guide elements in a direction perpendicular to the sliding plane, and sliding of the guide elements in the lengthwise direction of the adjustment members.
According to another advantageous embodiment of the invention, at least some of the guide elements each comprise pressure means for pressing a flow to be diverted against the rollers from above. A pressure means of this type is of advantage especially in cases where the imbricated flow consists of particularly light-weight printed products. The pressure means ensures in this case that sufficient friction exists between the rollers and the imbricated flow of printed products to drive the flow in the desired way.
According to an advantageous further improvement of that embodiment, the pressure means take the form of a ball retained in a ring that is connected with the guide element so as to allow vertical movement of the ball. The pressing force required is then derived from the weight of the ball as such. The fact that the ball is allowed to rotate in the ring keeps friction between the pressure means and the imbricated flow of printed products at a minimum level.
According to another advantageous embodiment of the invention, a first and a second clamping rail are arranged on a forward and on a rear end of the roller table, respectively. The adjustment member is detachably mounted on the clamping rails by means of clamping screws. This embodiment allows, in a constructionally especially simple way, the position of the adjustment member to be varied in the sliding plane. For, in order to vary the position of the adjustment member, it is only necessary to untighten the clamping screws and to fix the adjustment member in a different orientation between the two clamping rails by retightening the clamping screws appropriately. This embodiment also permits a plurality of adjustment members to be arranged above the roller table in the described way, without a need to provide separate adjusting means for each adjustment member.
According to another advantageous embodiment of the invention, the guide elements are delimited, in the transport direction defined by the rollers, by two plane sliding surfaces, which are arranged parallel one to the other and perpendicular to the transport direction. The guide elements are positioned along the adjustment member so as to ensure that, irrespective of the position of the adjustment members, every two neighboring guide elements are in contact one with the other along their sliding surfaces. The guide elements thus provide continuous guidance for the imbricated flow of printed products, irrespective of the position of the adjustment member, thereby preventing the imbricated flow from ducking below or between the guide elements.